Multi-Tower Effect Analysis of Long-Span Suspension Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 1940-1944
Author(s):  
Xiao Yan Zheng ◽  
Zhuo De Feng ◽  
Yue Xu
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Bending Moment ◽  
Suspension Bridge ◽  
Finite Element Models ◽  
Performance Difference ◽  
Displacement Effect ◽  
Effect Analysis ◽  
Long Span ◽  
Behavior Study

As a new bridge system, mechanics behavior study on long-span multi-tower suspension is also very deficiency. The existence of center towers is the origin of performance difference between multi-tower suspension bridge and the traditional one. Based on the Midas/Civil platform, the paper takes a three tower suspension bridge as project reference, establishes finite element models of suspension bridge, which the main span is longer than one kilometer and towers from two to seven. Moreover, the structural property is analyzed separately, which bending moment and displacement effect of girder and tower along with the tower number changes is considered. Natural frequency differences of the model bridges are also paid attention on.

Dynamics Analysis of Refrigeration Compressor Based on Finite Element and Experimental Modes

2012 ◽  
Vol 499 ◽  
pp. 238-242
Author(s):  
Li Zhang ◽  
Hong Wu ◽  
Yan Jue Gong ◽  
Shuo Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Modal Analysis ◽  
Natural Frequency ◽  
High Precision ◽  
3D Model ◽  
Finite Element Models ◽  
Dynamics Analysis ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

Based on the 3D model of refrigeration's compressor by Pro/E software, the analyses of theoretical and experimental mode are carried out in this paper. The results show that the finite element models of compressor have high precision dynamic response characteristics and the natural frequency of the compressor, based on experimental modal analysis, can be accurately obtained, which will contribute to further dynamic designs of mechanical structures.

Study on Long Span Transmission Tower’s Typical Malfunctions

2011 ◽  
Vol 464 ◽  
pp. 187-190
Author(s):  
Hai Lin Wang ◽  
Qiang Gao
Keyword(s):  
Finite Element ◽  
Atmospheric Corrosion ◽  
Finite Element Models ◽  
Foundation Settlement ◽  
Transmission Tower ◽  
Long Span ◽  
Material Stiffness ◽  
Long Time

In this paper, several typical malfunctions of the long span transmission tower are analyzed, such as the material stiffness reduced by atmospheric corrosion over a long time, the loose of bolt joint caused by accidental factors or man-made sabotages, and foundation settlement. And establish finite element models according to the characteristics of different malfunctions. By analyzing the models, we discuss the safety of the long span transmission tower at different malfunctions. It is shown that the proposed method is of efficiency and practicality.

scholarly journals Wind-driven damage localization on a suspension bridge

2016 ◽  
Vol 11 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Marco Domaneschi ◽  
Maria Pina Limongelli ◽  
Luca Martinelli
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Identification ◽  
Structural Response ◽  
Suspension Bridge ◽  
Element Model ◽  
Damage Localization ◽  
Damage Scenarios ◽  
Long Span Bridges ◽  
Long Span

The paper focuses on extending a recently proposed damage localization method, previously devised for structures subjected to a known input, to ambient vibrations induced by an unknown wind excitation. Wind induced vibrations in long-span bridges can be recorded without closing the infrastructure to traffic, providing useful data for health monitoring purposes. One major problem in damage identification of large civil structures is the scarce data recorded on damaged real structures. A detailed finite element model, able to correctly and reliably reproduce the real structure behavior under ambient excitation can be an invaluable tool, enabling the simulation of several different damage scenarios to test the performance of any monitoring system. In this work a calibrated finite element model of an existing long-span suspension bridge is used to simulate the structural response to wind actions. Several damage scenarios are simulated with different location and severity of damage to check the sensitivity of the adopted identification method. The sensitivity to the length and noise disturbances of recorded data are also investigated.

scholarly journals Experimental Test of Circular Hollow Sections Solid Flanged Splice

2020 ◽  
Vol 8 (6) ◽  
pp. 3847-3851
Keyword(s):  
Finite Element ◽  
Bending Moment ◽  
Finite Element Models ◽  
Moment Capacity ◽  
Flexural Members ◽  
End Plate ◽  
Modes Of Failure ◽  
Aesthetic Appearance ◽  
Bolt Failure ◽  
Ultimate Moment

The use of circular hollow sections (CHS) have increased due to its aesthetic appearance and good mechanical properties. This research investigates the behavior of the bolted CHS splices with circular end plates under pure bending moment that allows the use of CHS as long flexural members. Three connections are tested and the corresponding finite element models are constructed. The finite element models are verified with the experimental results and showed acceptable agreement in terms of both ultimate moment capacity and load-displacement curves. Three modes of failure are observed where the first is pure bolt failure, the second is pure end plate yielding while the third is a combination of the two modes where end plate plastifies accompanied by bolt failure. Stiffness is also observed and is found to be greatly affected by the thickness of the end plate

scholarly journals Feasibility Study on Tension Estimation Technique for Hanger Cables Using the FE Model-Based System Identification Method

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Kyu-Sik Park ◽  
Taek-Ryong Seong ◽  
Myung-Hyun Noh
Keyword(s):  
Finite Element ◽  
System Identification ◽  
Boundary Conditions ◽  
Natural Frequency ◽  
Inverse Analysis ◽  
Finite Element Models ◽  
Fe Model ◽  
Identification Methods ◽  
System Identification Method ◽  
Model Based

Hanger cables in suspension bridges are partly constrained by horizontal clamps. So, existing tension estimation methods based on a single cable model are prone to higher errors as the cable gets shorter, making it more sensitive to flexural rigidity. Therefore, inverse analysis and system identification methods based on finite element models are suggested recently. In this paper, the applicability of system identification methods is investigated using the hanger cables of Gwang-An bridge. The test results show that the inverse analysis and systemic identification methods based on finite element models are more reliable than the existing string theory and linear regression method for calculating the tension in terms of natural frequency errors. However, the estimation error of tension can be varied according to the accuracy of finite element model in model based methods. In particular, the boundary conditions affect the results more profoundly when the cable gets shorter. Therefore, it is important to identify the boundary conditions through experiment if it is possible. The FE model-based tension estimation method using system identification method can take various boundary conditions into account. Also, since it is not sensitive to the number of natural frequency inputs, the availability of this system is high.

Mechanics Characteristics Study for Cable-Stayed-Suspension Bridges

2011 ◽  
Vol 243-249 ◽  
pp. 1817-1825
Author(s):  
Jing Qiu ◽  
Rui Li Shen ◽  
Huai Guang Li
Keyword(s):  
Finite Element ◽  
Suspension Bridge ◽  
Simulation Method ◽  
Suspension Bridges ◽  
Preliminary Design ◽  
Structural System ◽  
Long Span Bridges ◽  
Long Span ◽  
Element Simulation ◽  
Mechanics Characteristics

As a composite structure, the cable-stayed-suspension bridge is characterized by relatively new structure, great overall stiffness and long-span capacity, which has been proposed for the design of some extra long-span bridges. In order to research further into the mechanics characteristics of this type of structural system, the proposed preliminary design of a cable-stayed-suspension bridge with a main span of 1800m is analyzed by means of finite element simulation method. The advantages on overall stiffness in the cable-stayed-suspension bridge are summarized in comparison with the three-span suspension bridge and the single-span suspension bridge. Then, the reasons for the fatigue of the longest suspension cables in the cable-stayed-suspension bridge are also discussed in this paper.

Nonlinear Stability Analysis of Long-Span Suspension Bridge Cable Tower

2014 ◽  
Vol 1030-1032 ◽  
pp. 802-806
Author(s):  
Xu Luo ◽  
Xin Sha Fu ◽  
Li Xiong Gu ◽  
Lu Rong Cai
Keyword(s):  
Finite Element ◽  
Nonlinear Stability ◽  
Geometrical Nonlinearity ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Design Calculation ◽  
Safety Control ◽  
Finite Element Software ◽  
Long Span ◽  
The Stability

The cable tower is the bearing component of long-span suspension bridges, and its structure is very high and bear large force, which determines the stability and is the key of safety control. As for the height of the main tower of a long-span suspension bridge up to 195.3 m, the finite element software ANSYS is used to establish a three-dimensional finite element model (FEM), and the effects of geometric nonlinearity and material nonlinearity on the stability of the main tower are analyzed. The calculation results show that geometrical nonlinearity and material defects have significant influence on the main tower stability, and the nonlinear stability should be considered under wind load in the design calculation.

scholarly journals Parametric analysis of the dynamic characteristics of a long-span three-tower self-anchored suspension bridge with a composite girder

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Feifei Shao ◽  
Zhijun Chen ◽  
Hanbin Ge
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Suspension Bridge ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Design Parameters ◽  
Long Span ◽  
Bending Mode ◽  
Main Cables ◽  
Central Buckle

Abstract Three-tower self-anchored suspension bridge (TSSB) is more and more favored because of its beautiful structure and strong adaptability to terrain and geological conditions. However, there are few engineering practices and related researches on super long-span three-tower self-anchored suspension bridges. A three-dimensional finite element model for the Fenghuang Yellow River Bridge, with the world’s longest span of its kind under construction, is established using the ANSYS finite element program, and the structural dynamic characteristics of the super long-span TSSB are studied and compared with those of several bridges of the same type or with similar spans. In addition, the influence of the key design parameters such as the stiffening girder stiffness, tower stiffness, main cable and suspender stiffness, central buckle, and longitudinal constraint system on the dynamic characteristics of the structure is analyzed. The results show that the first mode of the TSSB is longitudinal floating, the lower-order modes are dominated by vertical bending modes, while the higher-order modes are primarily vibration modes of the main cables, and the torsional modes exhibit strong coupling with the lateral sway of the towers and main cables. The frequency of the first antisymmetric vertical bending mode of the TSSB has an inversely proportional relationship with the main span length. Compared with a double-tower ground-anchored suspension bridge and cable-stayed bridge with similar spans, the TSSB has the lowest frequency for the first antisymmetric vertical bending mode and the highest frequency for the first symmetric vertical bending mode, with a more pronounced coupling with the towers and main cables in the torsional modes. Analysis of the structural parameters shows that the frequencies of the longitudinal floating mode, first antisymmetric vertical bending mode, first symmetric vertical bending mode, and first torsional mode are most sensitive to the longitudinal bending stiffness of the side tower, central buckle, vertical bending stiffness of the stiffening girder, and torsional stiffness of the stiffening girder, respectively. The research findings and relevant conclusions can provide basic data for response analysis of long-span TSSBs under dynamic loads and offer an engineering reference for the design of similar bridges around the world.

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